Konrick v. Exxon Mobil Corporation et al, No. 2:2014cv00524 - Document 69 (E.D. La. 2016)
Court Description: ORDER AND REASONS granting defendant's motion 32 to exclude Drs. Harrison, Bearer, and Waters.. Signed by Judge Sarah S. Vance on 2/4/16. (jjs)
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Konrick v. Exxon Mobil Corporation et al Doc. 69 UNITED STATES DISTRICT COURT EASTERN DISTRICT OF LOUISIANA NATALIE KONRICK CIVIL ACTION VERSUS NO: 14-524 EXXON MOBIL CORPORATION, AND CHALMETTE REFINING, LLC SECTION: R ORD ER AN D REASON S Defendants Exxon Mobil Corporation and Chalm ette Refining, LLC m ove to exclude the testim ony of plaintiff's three general causation experts, Drs. Robert Harrison, Cynthia Bearer, and Laurel Waters. Having reviewed the parties' briefs, along with each expert's report and the studies cited therein, the Court grants defendants' m otion because it finds that each doctor's general causation opinion is based on an unreliable m ethodology. I. BACKGROU N D Plaintiff Natalie Konrick filed this personal injury and wrongful death action against defendants. Plaintiff alleges that, while pregnant, she worked as a security guard at the Exxon Chalm ette Refinery, where her tasks included checking crew m em bers' identification badges and bags as they entered the Dockets.Justia.com facility.1 According to plaintiff, this work exposed her and her fetus to toxic substances, which caused her to suffer fetal dem ise and a stillbirth delivery.2 Plaintiff further alleges that defendants negligently designed and m aintained the refinery and that they negligently failed to warn refinery personnel of the reproductive hazards associated with exposure.3 She seeks dam ages for the physical and em otional traum a associated with her stillbirth, as well as for the wrongful death of her stillborn fetus.4 Plaintiff's total em ploym ent at the refinery lasted from J anuary to April 20 13. On April 9, 20 13, plaintiff was adm itted to the hospital after experiencing pelvic pressure, decreased fetal m ovement, and vaginal leakage.5 The next day, plaintiff's doctor induced labor, and plaintiff "delivered her stillborn daughter."6 An autopsy revealed that the child was 27 weeks of gestational age and that it exhibited various anatom ical anom alies, including m icrocephaly (a term which, according to plaintiff's expert pathologist, m eans 1 R. Doc. 1 at 2-3. 2 Id. at 7, 9, 10 . 3 Id. at 7-9. 4 Id. at 9-10 . 5 Id. at 5. 6 Id. 2 "severely low head circum ference"),7 a cleft palate, and nonunion of the m andibular sym physis.8 The autopsy report identified the likely cause of fetal dem ise as "decreased uteroplacental blood flow with subsequent obliterative fetal vasculopathy and fetal hypoxem ia."9 The report noted that plaintiff reported having been exposed to benzene during pregnancy, but that while "benzene has been shown to cross the hum an placenta[,] . . . . [the] effects of benzene exposure in pregnant wom en [are] not well understood."10 Plaintiff alleges that her stillbirth resulted from general and acute exposure to toxic substances at the refinery. Plaintiff's com plaint alleges exposure to two substances in particular: benzene and hydrogen sulfide.11 Specifically, plaintiff alleges that because her guard post was located near the refinery's dock, "she was exposed to benzene from the loading and unloading of ships and barges on a daily basis."12 In addition, plaintiff alleges that a pipeline leak on the m orning of April 3 exposed her to elevated levels of 7 R. Doc. 32-8 at 8. 8 R. Doc. 32-11 at 3. 9 Id. at 6. 10 Id. 11 R. Doc. 1 at 2-3. 12 Id. 3 benzene and hydrogen sulfide over the course of several days.13 Plaintiff's exposure expert, Dr. David Mitchell, a forensic m eteorologist, expands the list of chem icals at issue. Using an air dispersion m odel, Dr. Mitchell estim ates the m axim um concentrations of various substances in the air as a result of em issions within the refinery.14 Based on this analysis, he opines that plaintiff was exposed to "significant" or "non-zero" levels of benzene and hydrogen sulfide, as well as toluene, ethyl-benzene, xylene, and other chem ical com pounds.15 Dr. Mitchell does not, however, quantify plaintiff's level of exposure to any particular substance. To dem onstrate that occupational exposure caused her stillbirth, plaintiff offers the testim ony of three m edical experts: Drs. Harrison, Bearer, and Waters. In their expert reports, each expert opines that the exposures alleged by plaintiff and described by Dr. Mitchell can cause adverse reproductive outcom es of the type identified in plaintiff's com plaint. Defendants now m ove to exclude each expert's opinion, arguing that each is based on an unreliable m ethodology.16 13 Id. at 3. 14 R. Doc. 34-6 at 3. 15 Id. at 27. 16 R. Doc. 32-2. In a separate m otion, defendants also challenge the reliability of plaintiff's exposure expert, Dr. Mitchell. See R. Doc. 34. 4 II. LEGAL STAN D ARD In this toxic torts case, plaintiff alleges that general and acute exposure to benzene, hydrogen sulfide, and other substances caused her stillbirth at 27 weeks of gestation. Accordingly, plaintiff m ust show general causation--that these substances can cause stillbirths--and specific causation--that exposure to defendants' substances caused plaintiff's stillbirth. See Knight v. Kirby Inland Marine Inc., 482 F.3d 347, 351 (5th Cir. 20 0 7) ("General causation is whether a substance is capable of causing a particular injury or condition in the general population, while specific causation is whether a substance caused a particular individual's injury."). A court m ay adm it specific-causation evidence only after the plaintiff has produced adm issible evidence on general causation. See id. ("[I]f it concludes that there is adm issible general-causation evidence, the district court m ust determ ine whether there is adm issible specific-causation evidence."). A district court has considerable discretion to adm it or exclude expert testim ony under Rule 70 2. See Gen. Elec. Co. v. Joiner, 522 U.S. 136, 138– 39 (1997); Seatrax, Inc. v. Sonbeck Int'l, Inc., 20 0 F.3d 358, 371 (5th Cir. 20 0 0 ). Rule 70 2, which governs the adm issibility of expert witness testim ony, provides: 5 A witness who is qualified as an expert by knowledge, skill, experience, training, or education m ay testify in the form of an opinion or otherwise if: (a) the expert's scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determ ine a fact in issue; (b) the testim ony is based on sufficient facts or data; (c) the testim ony is the product of reliable principles and m ethods; and (d) the expert has reliably applied the principles and m ethods to the facts of the case. Fed.R.Evid. 70 2. In Daubert v. Merrell Dow Pharm s., Inc., the Suprem e Court held that Rule 70 2 requires the district court to act as a gatekeeper to ensure that "any and all scientific testim ony or evidence adm itted is not only relevant, but reliable." 50 9 U.S. 579, 589 (1993); see also Kum ho Tire Co., Ltd. v. Carm ichael, 526 U.S. 137, 147 (1999) (clarifying that the Daubert gatekeeping function applies to all form s of expert testim ony). The Court's gatekeeping function thus involves a two-part in quiry into reliability and relevance. First, the Court m ust determ ine whether the proffered expert testim ony is reliable. The party offering the testim ony bears the burden of establishing its reliability by a preponderance of the evidence. See Moore v. Ashland Chem . Inc., 151 F.3d 269, 276 (5th Cir. 1998). The reliability inquiry requires the Court to assess whether the reasoning or m ethodology underlying the expert's testim ony is valid. See Daubert, 50 9 U.S. at 592– 93. The aim is to exclude expert testim ony based m erely on subjective belief or unsupported 6 speculation. See id. at 590 . The Court in Daubert articulated a flexible, non-exhaustive, five-factor test to assess the reliability of an expert's m ethodology: (1) whether the expert's theory can be or has been tested; (2) whether the theory has been subject to peer review and publication; (3) the known or potential rate of error of a technique or theory when applied; (4) the existence and m aintenance of standards and controls; and (5) the degree to which the technique or theory has been generally accepted in the scientific com m unity. Id. at 593– 95. The Suprem e Court has em phasized, however, that these factors "do not constitute a 'definitive checklist or test.'" Kum ho, 526 U.S. at 150 (quoting Daubert, 50 9 U.S. at 593). Rather, district courts "m ust have considerable leeway in deciding in a particular case how to go about determ ining whether particular expert testim ony is reliable." Id. at 152. Courts have also considered whether experts are "proposing to testify about m atters growing naturally and directly out of research they have conducted independent of the litigation, or whether they have developed their opinions expressly for purposes of testifying." Daubert v. Merrell Dow Pharm s., Inc., 43 F.3d 1311, 1317 (9th Cir. 1995). They have exam ined whether the expert has adequately accounted for obvious alternative explanations. See Claar v. Burlington N.R.R., 29 F.3d 499, 50 2 (9th Cir. 1994). They have also asked whether the expert "is being as careful as he would be in his regular 7 professional work outside his paid litigation consulting." Sheehan v. Daily Racing Form , Inc., 10 4 F.3d 940 , 942 (7th Cir. 1997). A district court's gatekeeper function does not replace the traditional adversary system or the role of the jury within this system . See Daubert, 50 9 U.S. at 596. As the Suprem e Court noted in Daubert: "Vigorous cross-exam ination, presentation of contrary evidence, and careful instruction on the burden of proof are the traditional and appropriate m eans of attacking shaky but adm issible evidence." Id. The Fifth Circuit has held that, in determ ining the adm issibility of expert testim ony, district courts m ust accord proper deference to "the jury's role as the proper arbiter of disputes between conflicting opinions" and that, generally, "questions relating to the bases and sources of an expert's opinion affect the weight to be assigned that opinion rather than its adm issibility." United States v. 14.38 Acres of Land, More or Less Situated in Leflore Cnty ., Miss., 80 F.3d 10 74, 10 77 (5th Cir. 1996) (quoting Viterbo v. Dow Chem . Co., 826 F.2d 420 , 422 (5th Cir. 1987)) (internal quotation m arks om itted). Nonetheless, expert testim ony "m ust be reliable at each and every step or else it is inadm issible," and "[t]he reliability analysis applies to all aspects of an expert's testim ony: the m ethodology, the facts underlying the expert's opinion, the link between the facts and the conclusion, et alia." Knight, 482 F.3d at 355 (internal quotation m arks 8 om itted). If the "expert's opinion is based on insufficient inform ation, the analysis is unreliable." Paz v. Brush Engineered Materials, Inc., 555 F.3d 383, 388 (5th Cir. 20 0 9). In Joiner, the Suprem e Court explained that "nothing in either Daubert or the Federal Rules of Evidence requires a district court to adm it opinion evidence that is connected to existing data only by the ipse dixit of the expert." 522 U.S. at 146. Rather, "[a] court m ay conclude that there is sim ply too great an analytical gap between the data and the opinion proffered." Id.; see also LeBlanc v. Chevron USA, Inc., 396 F. App'x 94, 98 (5th Cir. 20 10 ). The Court next considers whether the expert's reasoning or methodology is relevant. The question here is whether the reasoning or m ethodology "fits" the facts of the case and will thereby assist the trier of fact to understand the evidence. See Daubert, 50 9 U.S. at 591. In fulfilling its role as a gatekeeper, the Court recognizes that "the courtroom is not the place for scientific guesswork, even of the inspired sort." Rosen v. Ciba– Geigy Corp., 78 F.3d 316, 319 (7th Cir. 1996). Rather, "[l]aw lags science; it does not lead it." Id. The Court is m indful of the following Suprem e Court guidance: [T]here are im portant differences between the quest for truth in the courtroom and the quest for truth in the laboratory. Scientific conclusions are subject to perpetual revision. Law, on the other 9 hand, m ust resolve disputes finally and quickly. The scientific project is advanced by broad and wide-ranging consideration of a m ultitude of hypotheses, for those that are incorrect will eventually be shown to be so, and that in itself is an advance. Conjectures that are probably wrong are of little use, however, in the project of reaching a quick, final, and binding legal judgm ent-often of great consequence--about a particular set of events in the past. We recognize that, in practice, a gatekeeping role for the judge, no m atter how flexible, inevitably on occasion will prevent the jury from learning of authentic insights and innovations. That, nevertheless, is the balance that is struck by Rules of Evidence designed not for the exhaustive search for cosm ic understanding but for the particularized resolution of legal disputes. Daubert, 50 9 U.S. at 596– 97. III. D ISCU SSION A. In tro d u ctio n Defendants contend that there is no scientific basis for concluding that exposure to benzene, hydrogen sulfide, or the other chem icals identified by plaintiff's exposure expert, Dr. Mitchell, can cause stillbirths at 27 weeks of gestation. To prove that these substances can cause stillbirths in the general population, plaintiff offers the testim ony of three experts: Drs. Harrison, Bearer, and Waters. Under Daubert, the Court's focus is on m ethodology. According to their reports, each expert relies heavily upon epidem iological studies concerning exposure to various toxins and adverse reproductive effects. Epidem iology provides the best evidence of general causation in toxic tort cases. See Brock 10 v. Merrell Dow Pharm s., Inc., 874 F .2d 30 7, 311 (5th Cir. 1989), m odified by 884 F.3d 166 (5th Cir. 1989); N orris v. Baxter Healthcare Corp., 397 F.3d 878, 882 (10 th Cir. 20 0 5) (stating "that epidem iology is the best evidence of general causation in a toxic tort case"). This is not to say that epidem iologic evidence "is a necessary elem ent in all toxic tort cases," but "it is certainly a very im portant elem ent." Brock, 874 F.2d at 313. Epidem iology is the study of "the incidence, distribution, and etiology of disease in hum an populations." Federal J udicial Center, Reference Manual on Scientific Evidence 551 (3d ed. 20 11). As the Fifth Circuit has explained: Epidem iology attem pts to define a relationship between a disease and a fact suspected of causing it.... To define that relationship, the epidem iologist exam ines the general population, com paring the incidence of the disease am ong those people exposed to the factor in question to those not exposed. The epidem iologist then uses statistical m ethods and reasoning to allow her to draw a biological inference between the factor being studied and the disease's etiology. Brock, 874 F.2d at 311. To determ ine whether a causal relationship exists between an agent and a disease, an epidem iologist m ust first identify an association. An association occurs when "two events (e.g., exposure to a chem ical agent and developm ent of disease) . . . occur m ore frequently together than one would expect by chance." Reference Manual at 552 n. 7. An association, by itself, is not 11 equivalent to causation. Id. at 552. Unlike an association, "[c]ausation is used to describe the association between two events when one event is a necessary link in a chain of events that results in the effect." Id. at 552 n. 7. The Reference Manual indicates that "[a]ssesssing whether an association is causal requires an understanding of the strengths and weaknesses of a study's design and im plem entation, as well as a judgm ent about how the study's findings fit with other scientific knowledge." Id. at 553. Because "all studies have 'flaws' in the sense of lim itations that add uncertainty about the proper interpretation of results," the key questions in evaluating epidem iologic evidence "are the extent to which a study's lim itations com prom ise its findings and perm it inferences about causation." Id. at 553. Once an association is found, "researchers consider whether the association reflects a true cause-effect relationship;" that is, whether "an increase in the incidence of disease am ong the exposed subjects would not have occurred had they not been exposed to the agent." Id. at 597– 98. Alternative explanations, "such as bias or confounding factors," should first be considered. Id. at 598. If alternative explanations are not present, researchers apply the "Bradford Hill criteria" to evaluate whether an agent could be a cause of a disease. See In re Breast Im plant Litig., 11 F. Supp. 2d 1217, 1233 (D. Colo. 1998). The Bradford Hill criteria are: (1) tem poral relationship; (2) 12 strength of the association; (3) dose-response relationship; (4) replication of findings; (5) biological plausibility; (6) consideration of alternative explanations; (7) cessation of exposure; (8) specificity of the association; and (9) consistency with other knowledge. Reference Manual at 60 0 . The Reference Manual cautions: There is no form ula or algorithm that can be used to assess whether a causal inference is appropriate based on these guidelines. One or m ore factors m ay be absent even when a true causal relationship exists. Sim ilarly, the existence of som e factors does not ensure that a causal relationship exists. Drawing causal inferences after finding an association and considering these factors requires judgm ent and searching analysis, based on biology, of why a factor or factors m ay be absent despite a causal relationship, and vice versa. Although the drawing of causal inferences is inform ed by scientific expertise, it is not a determ ination that is m ade by using an objective or algorithm ic m ethodology. Id. Under Daubert, "courts m ust carefully analyze the studies on which experts rely for their opinions before adm itting their testim ony." Knight, 482 F.3d at 355; see also Brock, 874 F.2d at 30 9– 10 ("[C]ourts m ust critically evaluate the reasoning process by which experts connect data to their conclusions in order for courts to consistently and rationally resolve the disputes before them ."); W agoner v. Exxon Mobil Corp., 813 F. Supp. 2d 771, 799 (E.D. La. 20 11) ("Whether epidem iological studies support an expert's 13 opinion on the question of general causation in a toxic tort case is critical to determ ining the reliability of the opinion."). Courts "m ay exclude expert testim ony based on epidem iological studies where the studies are insufficient, whether considered individually or collectively, to support the expert's causation opinion." Baker v. Chevron USA, Inc., 680 F. Supp.2d 865, 875 (S.D. Ohio 20 10 ) (citing Joiner, 522 U.S. at 156– 57). A court cannot exclude expert testim ony sim ply because it disagrees with the expert's conclusions, but an expert's conclusions m ust be connected to existing data by m ore than the m ere say-so of the expert. [C]onclusions and m ethodology are not entirely distinct from one another. Trained experts com m only extrapolate from existing data. But nothing in either Daubert or the Federal Rules of Evidence requires a court to adm it opinion evidence that is connected to existing data only by the ipse dixit of the expert. A court m ay conclude that there is sim ply too great an analytical gap between the data and the opinion offered. Joiner, 522 U.S. at 146. Courts have excluded expert opinions on causation based on epidem iologic and other scientific studies for a num ber of reasons. First, studies that "do not represent statistically significant results" m ay not provide a reliable foundation for a general causation opinion in a toxic torts case. LeBlanc, 396 F. App'x at 99 (citing Joiner, 522 U.S. at 145 (holding that a study showing a statistically insignificant increase in disease incidence 14 following exposure to the allegedly causal chem ical can be rejected by the district court as a foundation for the expert's opinion)). The results of epidem iological studies are often expressed in term s of a relative risk (RR) 17 or an odds ratio (OR).18 An RR or OR of 1.0 indicates that the num ber of observed incidences of a disease or condition equals that of expected cases. In contrast, a figure higher than 1.0 indicates that the num ber of observed incidences exceeds that of expected cases; in other words, it indicates a positive association. A study is considered statistically significant only when the results--e.g., RR or OR--are expressed with a 95% confidence interval, and when that interval does not include the num ber 1.0 . See Brock, 874 F .2d at 312. As the Fifth Circuit has explained: [I]f a study concluded that the relative risk for [a toxin] was 1.30 , which is consistent with a 30 % elevated risk of harm , but the confidence interval was from 0 .95 to 1.82, then no statistically significant conclusions could be drawn from this study because the relative risk, when adjusted by the confidence interval, includes 17 "The relative risk is a num ber which describes the increased or decreased incidence of the disease in question in the population exposed to the factor as com pared to the control population not exposed to the factor. . . . A relative risk of 1.0 m eans that the incidence of [the disease or condition] in the two groups were the sam e. A relative risk greater than 1.0 m eans that there [was m ore of the disease or condition in the group exposed to the factor]." Brock, 874 F.2d at 312. 18 "A m easure of association, often used in epidem iology. For exam ple, if 10 % of all people exposed to a chem ical develop a disease, com pared with 5% of people who are not exposed, then the odds of the disease in the exposed group are 10 / 90 = 1/ 9, com pared with 5/ 95 = 1/ 19 in the unexposed group. The odds ratio is (1/ 9)(1/ 19) = 19/ 9 = 2.1. An odds ratio of 1 indicates no association." Reference Manual at 291. 15 1.0 . Again, it is im portant to rem em ber that the confidence interval attem pts to express m athem atically the m agnitude of possible error, due to the above m entioned sources as well as others, and therefore a study with a relative risk of greater than 1.0 m ust always be considered in light of its confidence interval before one can draw conclusions from it. Id. Second, a study that provides m erely "a suggestion or possibility of a relationship is insufficient for a causation opinion." In re Breast Im plant Litig., 11 F. Supp. 2d at 1233; see also Knight, 482 F.3d at 353 ("Although the study's 'suggestion' could theoretically provide som e basis for the conclusion that diesel exhaust causes bladder cancer, it does not, as appellants argue, 'clearly support' that conclusion."). The sam e is true of a study that "only provides an arguable inferential starting point" for finding a causal relationship. LeBlanc, 396 F. App'x at 99. Studies that are inconclusive and m erely recom m end that further studies be done are likely to fall into this category. See In re Breast Im plant Litig., 11 F. Supp. 2d at 1231. This is not to suggest that studies m ust unequivocally support a general causation opinion, but they m ust provide m ore than a hypothesis. Third, a study that notes "that the subjects were exposed to a range of substances and then nonspecifically note[s] increases in disease incidence" can be disregarded. LeBlanc, 396 F. App'x at 99; see also Joiner, 522 U.S. at 146 16 (holding that an expert's reliance on a study was m isplaced when the subjects of the study "had been exposed to num erous potential carcinogens"); Knight, 482 F.3d at 353 ("Of all the organic solvents the study controlled for, it could not determ ine which led to an increased risk of cancer. . . . The study does not provide a reliable basis for the opinion that the types of chem icals appellants were exposed to could cause their particular injuries in the general population."). Likewise, studies that do not exam ine the precise disease or condition at issue m ay not provide good grounds for an expert's opinion. See Henricksen v. Conoco Phillips Co., 60 5 F. Supp. 2d 1142, 1171– 75 (E.D. Wa. 20 0 9) (calling into question the relevance of studies that did not study the specific disease at issue). Fourth, when a study's authors expressly disclaim the causal relationship that the expert relies upon the study to prove, the study likely does not provide a reliable basis for the expert's opinion. See Joiner, 522 U.S. at 145 (holding that a study did not support an expert's opinion on causation when the study was "unwilling to say that PCB exposure had caused cancer"); LeBlanc, 396 F. App'x at 10 0 ("The district court properly rejected the studies as supporting causation because the authors of the studies concluded that there was no proof of causation."); McClain v. Metabolife Int'l, Inc., 40 1 F.3d 1233, 1248 (11th Cir. 17 20 0 5) (criticizing an expert for drawing "unauthorized conclusions from lim ited data--conclusions the authors of the study do not m ake"). 18 B. D r. H arris o n Plaintiff's first general causation expert, Dr. Harrison, is a m edical doctor board certified in occupational and internal m edicine. As to general causation, Dr. Harrison states: "occupational exposure to organic solvents is a cause of adverse reproductive outcom es, including decreased uterine blood flow with fetal hypoxem ia leading to fetal dem ise."19 The reported basis for Dr. Harrison's conclusion is his review of published epidem iological reports and other relevant data, including "hum an case reports, anim al data, experim ental studies, laboratory data, m echanistic data, and other types of data as well, including unpublished studies."20 Specifically, Dr. Harrison cites 29 epidem iological studies, which he sum m arizes according to the observed outcom e and the reported results.21 In addition, Dr. Harrison states that he "followed generally accepted methodology for determining general causation," including application of the Bradford Hill criteria.22 Having reviewed the parties' briefings and subm issions, Dr. Harrison's report and deposition testim ony, and the relevant scientific literature, the 19 R. Doc. 32-7 at 17. ("Dr. Harrison Report"). 20 Id. at 3. 21 Id. at 20 -22. 22 Id. at 3-4. 19 Court finds that Dr. Harrison's general causation opinion is not grounded in a reliable m ethodology. Dr. Harrison's m ethodology is flawed because he relies on m ultiple studies that do not reliably support his conclusion. First, Dr. Harrison relies on a num ber of studies that do not isolate exposure to the substances at issue, or do not provide exposure m etrics. Second, m any of the studies upon which Dr. Harrison relies exam ine the incidence of spontaneous abortion or m iscarriage, rather than stillbirth, the outcom e at issue in this case. Third, Dr. Harrison relies on studies that do not exhibit statistically significant results. Finally, in several instances, Dr. Harrison cherry-picked data from studies that do not otherwise support his conclusion, reached conclusions that the authors of the study did not m ake, and failed to explain contrary results. Com pounding these shortcom ings is that, despite citing studies that are inconsistent in both their subject m atter and their results, Dr. Harrison does not present a m eaningful analysis in which he reconciles the contradicting results and explains their relevance to the facts of this case. 1. Dr. Harrison's Reliance on Studies that Do Not Isolate Exposure to the Substances at Issue or Do N ot Provide Exposure Metrics A basic flaw in Dr. Harrison's m ethodology is that he relies heavily on studies that focus on "solvents" or "organic solvents" as a class, instead of the 20 specific substances that allegedly caused plaintiff's stillbirth.23 See Glastetter v. N ovartis Pharm s. Corp., 252 F.3d 986, 990 (8th Cir. 20 0 1) ("Even m inor deviations in m olecular structure can radically change a particular substance's properties and propensities." (citing Schudel v. Gen. Elec. Co., 120 F.3d 991, 996-97 (9th Cir. 1997))); Wennborg, H., et al., Adverse Reproduction Outcom es Am ong Em ploy ees W orking in Biom edical Research Laboratories, 28 SCAND. J . ENV'T HEALTH 5 (20 0 2) (noting "different types of solvents [m ay] have different effects on reproduction . . . ."); Khattak, S., et al., Pregnancy Outcom e Follow ing Gestational Exposure to Organic Solvents, 281 J . AM. MEDICAL ASS'N 110 6 (1999) ("[O]rganic solvents, although traditionally clustered together, are a diverse group of com pounds that should not be expected to cause sim ilar patterns of reproductive toxic effects."). Because these studies do not isolate exposure to benzene, hydrogen sulfide, or the chem icals identified by Dr. Mitchell from exposure to other substances, they cannot reliably support Dr. Harrison's opinion that the exposure alleged by plaintiff can cause stillbirths in the general population. See Leblanc, 396 23 The parties do not dispute that the term "organic solvents" refers to a broad range of substances that includes benzene, toluene, heptane, and hexane, am ong others. R. Doc. 44 at 12; R. Doc. 53 at 5. Plaintiff apparently concedes, however, that hydrogen sulfide is not an organic solvent. See R. Doc. 44 at 12 (noting that "organic solvents are carbon-based solvents capable of dissolving or dispersing one or m ore substances and concluding that "benzene, toluene, heptane, and hexane are all organic solvents"). 21 F. App'x at 99 (noting a study indicating "that the subjects were exposed to a range of substances and then nonspecifically note increases in disease incidence" can be disregarded); Knight, 482 F.3d at 353 (finding study that focused on organic solvents as a class without determ ining which solvent led to an increased risk of cancer did not provide reliable basis for opinion that benzene could cause plaintiffs' specific injuries); Am orgianos v. Nat'l R.R. Passenger Corp., 30 3 F.3d 256, 270 (2d Cir. 20 0 2) (excluding general causation expert who relied upon articles that "involved individuals who were exposed to a variety of solvents, m any of which were not contained in the paint [plaintiff] used"). For instance, Dr. Harrison's expert report cites, without any explanation or elaboration, Attarchi, M., et al., Assessm ent of Tim e to Pregnancy and Spontaneous Abortion Status Follow ing Occupational Exposure to Organic Solvents, 85 INT'L ARCHIVES OCCUPATIONAL ENVTL HEALTH 295 (20 12),24 in support of his general causation opinion. Dr. Harrison's report fails to note that the workers in the study were exposed to a num ber of different organic solvents, including form aldehyde, phenol, hexane, and chloroform--substances to which, as Dr. Harrison admitted in his deposition,25 24 Dr. Harrison Report at 20 . 25 R. Doc. 53-1 at 5. 22 plaintiff was never exposed. Nor does the report acknowledge the study's guidance that because workers "m ay have exposure to a m ixture of organic solvents, it is difficult to attribute spontaneous abortion to any specific solvent." Sim ilarly, Dr. Harrison's report cites Agnesi, R., et al., Risk of Spontaneous Abortion and Maternal Exposure to Organic Solvents in the Shoe Industry , 69 INT'L ARCHIVES OCCUPATIONAL ENVTL HEALTH 311 (1997),26 without noting that the workers involved were exposed prim arily to ethylacetate, m ethylethylketone, hexane isom ers, and cyclohexane. Though Dr. Harrison acknowledged that none of these substances is at issue,27 his report fails to explain why this study is relevant to plaintiff's case. Dr. Harrison's reliance on a num ber of other studies is sim ilarly flawed. See Garlantezec, R., et al., Maternal Occupational Exposure to Solvents and Congenital Malform ations, 66 OCCUPATIONAL ENVL MEDICINE 456 (20 0 9) (exam ining risks associated with m aternal exposure to solvents as a group, without specifying which "specific chem ical classes of solvents" were responsible for observed increase in incidence of congenital m alform ation); 28 Holm berg, P., et al., Oral Clefts and Organic Solvent Exposure During 26 Dr. Harrison Report at 20 . 27 R. Doc. 53-1 at 9. 28 Dr. Harrison Report at 20 . 23 Pregnancy , 50 INTL ARCHIVES OCCUPATIONAL ENVTL HEALTH 371 (1982) (noting em ployees were exposed to a range of solvents, including lacquer petrol, xylene, and m ethylethylketone); 29 Huel, G., et al., Evidence for Adverse Reproductive Outcom es Am ong W om en Microelectronic Assem bly W orkers, 47 BRITISH J . INDUS. MEDICINE 40 0 (1990 ) (noting em ployees were potentially exposed to, am ong other solvents, chorofluorocarbons, chlorinated hydrocarbons, glycol ethers, and alcohol).30 Dr. Harrison also cited a num ber of studies that specifically exam ined substances such as glycol ethers and others that are absent from plaintiff's com plaint and Dr. Mitchell's exposure analysis. See e.g., Brender, J ., et al., Maternal Residential Proxim ity to Chlorinated Solvent Em issions and Birth Defects in Offspring, 13 ENVTL HEALTH 96 (20 14) (exam ining risks associated with exposure to carbon tetrachloride, ethyl chloride, trichloroethane, and other chlorinated solvents); 31 Cordier, S., et al., Congenital Malform ation and Maternal Occupational Exposure to Gly col Ethers, 8 EPIDEMIOLOGY 355 (1997) (evaluating risk of congenital 29 Id. at 21. 30 Id. 31 Id. at 20 . 24 m alform ations related to glycol ether exposure); 32 Kyyronen, P., et al., Spontaneous Abortions and Congenital Malform ations Am ong W om en Exposed to Tetrachloroethy lene in Dry Cleaning, 43 J . EPIDEMIOLOGY COMMUNITY HEALTH 346 (1989) (finding exposure to tetrachloroethylene significantly associated with spontaneous abortions).33 Dr. Harrison has made no attem pt to explain why these studies can reliably support the conclusion that the exposure to benzene, hydrogen sulfide, or any of the other chem icals at issue can cause stillbirths or congenital anom alies. Without dem onstrating how this literature applies to the specific exposures alleged by plaintiff, Dr. Harrison's reliance on these studies leaves "too great an analytical gap between the data and the opinion proffered." Joiner, 522 U.S. at 146. Dr. Harrison's reliance on studies that do not quantify exposure levels is equally problem atic. For instance, m any of the studies on which Dr. Harrison relies exam ined wom en in certain occupational groups, rather than directly exam ining exposure to benzene, hydrogen sulfide, or any other chem ical at issue. See Axelsson, G., et al., Exposure to Solvents and Outcom e of Pregnancy in University Laboratory Em ploy ees, 41 BRITISH J . INDUS. MEDICINE 30 5 (1984) (exam ining outcom e of pregnancy am ong personnel 32 Id. 33 Id. at 21. 25 em ployed in university laboratory and noting "laboratory work is a general term that im plies exposure to a variety of agents"); 34 Axelsson, G. and Molin, I., Outcom e of Pregnancy Am ong W om en Living Near Petrochem ical Industries in Sw eden, 17 INTL J . EPIDEMIOLOGY 363 (1988) (finding increase in m iscarriages am ong wom en who worked for petrochem ical com panies, without any elaboration as to the chem icals to which the workers were exposed other than note that "a large num ber of chem icals, including ethylene oxide, are used at these plants"); 35 Heidam , L., Spontaneous Abortions Am ong Dental Assistants, Factory W orkers, Painters, and Gardening W orkers: A Follow Up Study , 38 J . EPIDEMIOLOGY COMMUNITY HEALTH, 149 (1984) (exam ining risk of spontaneous abortion among women in various professions, but acknowledging that "information on chem ical exposure is not precise, and intensity and tim e of exposure in the pregnancy is unknown").36 While som e of these occupations m ay be an im precise proxy for exposure to the substances at issue here, these studies do not indicate what substances and at what levels the workers were actually exposed. Moreover, given the wide range of occupations at issue--the studies 34 Id. at 20 . 35 Id. 36 Id. 26 focus on dental hygienists, painters, gardeners, laboratory technicians, factory workers, and others--it is likely that workers were exposed to a wide range of substances, any one of which could potentially account for the observed outcom es. See ATSDR, Toxicological Profile for Benzene, 225 (20 0 7) (highlighting "problem s in controlling for concom itant exposures to other chem icals" as a factor lim iting studies on the reproductive effects of occupational benzene exposure). 2. Studies that Focus on Spontaneous Abortion Miscarriage, Instead of Later-Stage Pregnancy Loss or Second, m any of the studies upon which Dr. Harrison relies exam ined the risk of spontaneous abortions or m iscarriage--term s which, according to plaintiff's expert neonatologist, refer to a loss of pregnancy before the twentieth week of gestation.37 By contrast, plaintiff's pregnancy loss occurred at 27 weeks of gestation. Medical experts generally refer to such late-stage pregnancy loss as stillbirth.38 In his deposition, Dr. Harrison acknowledged the distinction between these outcom es: Q. The Xu, X-u, paper dealt with spontaneous abortion, correct? A. Correct. 37 R. Doc. 32-9 at 4. 38 Id. 27 Q. And if--and can we agree that Miss Konrick [did] not suffer spontaneous abortion, correct? A. Correct.39 Nonetheless, Dr. Harrison's report cites, without any explanation, num erous studies that exam ine the association between solvent exposure and m iscarriage or spontaneous abortion. See e.g., Agnesi, R., et al., Risk of Spontaneous Abortion and Maternal Exposure to Organic Solvents in the Shoe Industry , 69 INT'L ARCHIVES OCCUPATIONAL ENVTL HEALTH 311 (1997); 40 Axelsson, G., et al., Exposure to Solvents and Outcom e of Pregnancy in University Laboratory Em ploy ees, 41 BRITISH J . INDUS. MEDICINE 30 5 (1984); 41 Lindbolm , M.L., et al., Effects of Parental Occupational Exposure to Solvents and Lead on Spontaneous Abortion, 18 SCAND. J . WORK, ENVT, HEALTH 37 (1992); 42 Ng, T., et al., Risk of Spontaneous Abortion in W orkers Exposed to Toluene, 49 BRITISH J . INDUS. MEDICINE 80 4 (1992); 43 Xu, X., et al., Association of Petrochem ical Exposure w ith Spontaneous Abortion, 55 39 R. Doc. 53-1 at 6. 40 Dr. Harrison Report at 20 . 41 Id. 42 Id. at 21 43 Id. 28 OCCUPATIONAL ENVL MEDICINE 31 (1998).44 Dr. Harrison's expert report does not elaborate on these citations. Nor does it explain why these studies are relevant, even though the workers involved were exposed to solvents earlier in their pregnancies than plaintiff alleges, and they experienced an injury that Dr. Harrison acknowledges to be different from plaintiff's own. Dr. Harrison's failure to explain his reliance on these studies dim inishes his reliability. See Knight, 482 F.3d at 355 ("[T]he expert's testim ony m ust be reliable at each and every step or else it is inadm issible."). 3. Studies that Do Not Exhibit Statistically Significant Results Another weakness in Dr. Harrison's m ethodology is his reliance on studies exhibiting results that do not reach statistical significance. As the Fifth Circuit holds, studies "showing a statistically insignificant increase in disease incidence following exposure to the alleged causal chem ical can properly be rejected by the district court as a foundation for the expert's opinion." Leblanc, 396 F. App'x at 99 (citing Joiner, 522 U.S. at 145). Som e of the studies upon which Dr. Harrison relies did not produce statistically significant results, and his reliance on them is therefore questionable.45 See Axelsson, G., 44 Id. at 22. 45 Though plaintiff characterizes som e of these studies as statistically significant, she does not elaborate or provide any argum ent to support her position. As the Fifth Circuit holds, "if the confidence interval [of an epidem iological study] is so great that it 29 et al., Exposure to Solvents and Outcom e of Pregnancy in University Laboratory Em ploy ees, 41 BRITISH J . INDUS. MEDICINE 30 5 (1984); 46 Heidam , L., Spontaneous Abortions Am ong Dental Assistants, Factory W orkers, Painters, and Gardening W orkers: A Follow Up Study , 38 J . EPIDEMIOLOGYCOMMUNITYHEALTH, 149 (1984); 47 Hemminki, O., et al., Low Birthw eight, Congenital Malform ations, and Spontaneous Abortions Am ong Dry -Cleaning W orkers in Scandinavia, 16 SCAND. J . WORK, ENV'T, HEALTH, 163 (1990 ); 48 Kyyronen, P., et al., Spontaneous Abortions and Congenital Malform ations Am ong W om en Exposed to Tetrachloroethy lene in Dry Cleaning, 43 J . EPIDEMIOLOGY COMMUNITY HEALTH 346 (1989); 49 Wennborg, Adverse Reproductive Outcom es Am ong Em ploy ees W orking in Biom edical Research Laboratories, 28 SCAND. J . WORK, ENV'T, HEALTH 5 (20 0 2).50 includes the num ber 1.0 , then the study will be said to show no statistically significant association between the factor and the disease." Brock, 874 F.2d at 312. In each of these studies, the 95% confidence interval includes 1.0 . Contrary to plaintiff's contention, such studies are not statistically significant. 46 Dr. Harrison Report at 20 . 47 Id. 48 Id. 49 Id. at 21. 50 Id. 30 4. Dr. Harrison Cherry -Picked Data, Reached Conclusions that the Authors of the Studies Did Not Make, and Failed to Explain Contrary Results In several instances, Dr. Harrison cites studies selectively, highlighting only data that supports his position in a way that underm ines the reliability of his m ethodology. For exam ple, Dr. Harrison's expert report cites Laum on, B., et al., Exposure to Organic Solvents During Pregnancy and Oral Clefts: A Case Control Study , 10 REPROD. TOXICOLOGY 15 (1996),51 for its observation of an association between oral clefts (such as the cleft palate observed in plaintiff's fetus) and m aternal exposure to any organic solvent. The sam e study, however, separately exam ined the risks associated with exposure to arom atic solvents--a sub-category of solvents that includes benzene--and did not observe a statistically significant association. That Dr. Harrison disregards this result in favor of other, less specific data is problem atic and suggests a m ethodology driven by an attem pt to achieve a particular result. Rink v. Chem inova, Inc., 40 0 F.3d 1286, 1293 n. 7 (11th Cir. 20 0 5) ("In evaluating the reliability of an expert's m ethod, however, a district court m ay properly consider whether the expert's m ethodology has been contrived to reach a particular result." (citing Joiner, 522 U.S. 15 146)). 51 Id. 31 Sim ilarly, Dr. Harrison cites Lindbohm , M.L., et al., Spontaneous Abortions Am ong Rubber W orkers and Congenital Malform ations in their Offspring, 9 SCAND. J . WORK, ENV'T, HEALTH 85 (1983),52 for its finding that em ployees of a rubber factory's footwear departm ent were at an increased risk of spontaneous abortion. Dr. Harrison's report fails to m ention that the sam e study found no such association am ong wom en em ployed in the rubber factory's tire departm ent--or in any other profession that researchers exam ined. Moreover, Dr. Harrison relies on this study despite the authors' conclusion that their observations involving the factory's footwear and tire departm ents were "contradictory" and that m ore studies were needed to investigate "the role for solvents in the etiology of spontaneous abortions." See McClain v. Metabolife Int'l, Inc., 40 1 F.3d 1233, 1248 (11th Cir. 20 0 5) (criticizing an expert for drawing "unauthorized conclusions from lim ited data--conclusions the authors of the study do not m ake"). Finally, Dr. Harrison cites Axelsson, G. and Molin, I., Outcom e of Pregnancy Am ong W om en Living Near Petrochem ical Industries in Sw eden, 17 INTL J . EPIDEMIOLOGY 363 (1988),53 which exam ined pregnancy outcom es am ong wom en residing near several petrochem ical plants. Though 52 Id. 53 Id. at 20 . 32 the study found no association between am bient air exposure and increased pregnancy loss, it did observe increased m iscarriages am ong a sm all subset of wom en who worked at one petrochem ical plant. The study noted, however, that its sam ple of petrochem ical plant em ployees was sm all and that the authors were in the process of conducting a second, m ore extensive study to determ ine whether work at the plant increased a wom an's risk of m iscarriage. In the follow-up study, which Dr. Harrison's report fails to m ention, the authors found that "[t]he results do not indicate the presence of an increased risk today" among petrochemical plant em ployees. Axelsson, G. and Rylander, R., Outcom e of Pregnancy in W om en Engaged in Laboratory W ork at a Petrochem ical Plant, 16 AM. J . INDUS. MEDICINE 539 (1989). Dr. Harrison's failure to acknowledge this result underm ines his reliability. 5. Sum m ary In light of the Court's exam ination of the studies cited by Dr. Harrison, it is apparent that he relies on a collection of divergent studies that either do not isolate the relevant substances, do not exam ine the exposure outcom e at issue, or do not exhibit statistically significant results. In addition, Dr. Harrison exhibits a willingness to disregard contrary or inconsistent results, even within the studies upon he relies. 33 Com pounding these m ethodological shortcom ings is that, despite citing a body of literature that is inconsistent in both its subject m atter and its results, Dr. Harrison fails to present a m eaningful analysis in which he reconciles the various studies and explains their relevance to the facts of this case. Instead of explaining how he used the literature to reach his conclusion, Dr. Harrison's report sim ply lists a num ber of studies, sum m arizes their findings (occasionally omitting results that undermine his position), and states a conclusion. Moreover, although Dr. Harrison's report states that he "evaluate[d] all the data based upon recognized scientific factors (the Bradford Hill criteria)," it provides no actual Bradford Hill analysis. See Burst v. Shell Oil Co., No. CIV.A. 14-10 9, 20 15 WL 3620 111, at *5 (E.D. La. May 9, 20 15) (excluding Dr. Harrison's general causation opinion on whether benzene, as a com ponent of gasoline, can cause AML when Dr. Harrison's "report exhibit[ed] no application of the m ethodology he state[d] he applied"); Mallozzi v. EcoSMART Techs., Inc., No. 11-CV-2884 SJ F ARL, 20 13 WL 2415677, at *5 (E.D.N.Y. May 31, 20 13) (criticizing an expert for sim ply stating that he applied the Bradford Hill criteria without discussing his analysis). There is no evidence that he considered, for exam ple, strength of association, replication of findings, specificity of association, or any of the other criteria that epidem iologists use to draw causal inferences in their academ ic and 34 professional work. See Sheehan v. Daily Racing Form , Inc., 10 4 F.3d 940 , 942 (7th Cir. 1997) (noting that, under Daubert, a district court m ust "satisfy [itself] that the expert is being as careful as he would be in his regular professional work outside his paid litigation consulting"). Plaintiff resists this conclusion by noting that anim al studies have found an association between benzene exposure and spontaneous abortion.54 Other than Dr. Harrison's unsupported assurance that he "considered all relevant data, including . . . anim al data,"55 there is no evidence that Dr. Harrison considered the studies cited in plaintiff's brief. Moreover, even if Dr. Harrison had reviewed this literature, the Fifth Circuit has noted "the very lim ited usefulness of anim al studies when confronted with questions of toxicity." Brock, 874 F.2d at 313. Without any analysis dem onstrating how anim al study findings can predict exposure outcom es in hum ans, the studies cited by plaintiff "furnish[] at best speculative support for [plaintiff's] causation theory." Allen v. Pennsy lvania Eng'g Corp., 10 2 F.3d 194, 197 (5th Cir. 1996). For these reasons, the Court finds Dr. Harrison's methodology unreliable and grants defendants' m otion to exclude Dr. Harrison's general cassation opinion. 54 R. Doc. 44 at 11. 55 Dr. Harrison Report at 4. 35 C. D r. Be are r The Court turns to plaintiffs' second expert, neonatologist Dr. Bearer. As to general causation, Dr. Bearer states: "there exists a cause and effect relationship between . . . exposures to one or m ore of the following chem icals: benzene, hydrogen sulfide, toluene, xylene, heptane, and hexane" and "fetal dem ise."56 Dr. Bearer bases this conclusion on her review of "m edical and scientific literature . . . relating to the above identified toxins, workplace, and/ or adverse reproductive outcom es."57 Specifically, Dr. Bearer's report cites 19 epidem iological studies, each of which also appears in Dr. Harrison's report.58 Besides briefly sum m arizing each study, Dr. Bearer does not reveal any details of her analytical process. After reviewing Dr. Bearer's report and the m aterials upon which she relies, the Court finds Dr. Bearer's opinion inadm issible because it too is unreliable. As an initial m atter, the Court notes that Dr. Bearer does not identify any literature to support her opinion that is not also cited by Dr. Harrison.59 The Court has already found these studies inadequate to reliably 56 R. Doc. 32-5 at 3. ("Dr. Bearer Report"). 57 Id. 58 Id. at 4; R. Doc. 44-10 at 2. 59 Indeed, the Court notes that Drs. Harrison's and Bearer's literature reviews are, in m ost respects, identical, which raises questions about how m uch original analysis 36 support a general causation opinion, and Dr. Bearer's reliance on them is defective for the sam e reasons. Dr. Bearer's failure to explain her m ethodology is problem atic as well. Like Dr. Harrison, Dr. Bearer provides no analysis in which she reconciles contradicting results within the scientific literature. Nor does she offer any explanation for why the studies upon which she relies support her conclusion, despite their differences with the facts of this case. Indeed, the only m ention that Dr. Bearer m akes of her analytical approach appears in a single sentence in her expert report: "I will testify with reasonable professional certainty, rely ing on m ethodologies that are generally accepted in m y fields of speciality that there exists a cause and effect relationship between [plaintiff's] exposure . . . and her fetal dem ise."60 Without som e explanation of what these m ethodologies are or how she applied them to the scientific literature, Dr. Bearer's opinion is conclusory ipse dixit. Accordingly, the Court grants defendants' motion to exclude Dr. Bearer's general causation opinion because it is unreliable. actually underlies each expert's opinion. See Burst, 20 15 WL 3620 11 at *5 ("[T]o the extent Dr. Harrison relies on Dr. Infante' report and the studies cited therein, his opinion is inadm issible because it reflects no original analysis or evaluation of Dr. Infante's m ethodology or the studies upon which he relies."). 60 Dr. Bearer Report at 3 (em phasis added). 37 D. D r. W ate rs Plaintiff's final general causation expert is Dr. Waters, a m edical doctor board certified in anatom ic, clinical and pediatric pathology, and nuclear m edicine. In her expert report, Dr. Waters opines that "increasing benzene is associated with decreased growth of head circum ference and weight,"61 two anom alies observed in plaintiff's fetus. The reported basis for this conclusion is Dr. Waters' review of "studies regarding reproductive health and pregnancy outcom e adverse effects of petrochem ical exposure [sic]."62 Specifically, Dr. Waters cites five epidem iological studies, which she describes as "a sm all sam ple" of the relevant literature.63 As an initial m atter, the Court notes that although plaintiff--the party offering Dr. Waters' expert testim ony--bears the burden of establishing the reliability of Dr. Waters' m ethodology, she has presented no m eaningful opposition to defendants' m otion to exclude.64 Though plaintiff's opposition 61 R. Doc. 32-8 at 12. ("Dr. Waters Report"). 62 Id. at 11. 63 Id. 64 Plaintiff criticizes defendants for questioning her experts' m ethodologies, rather than conducting their own occupational exposure studies. R. Doc. 44 at 9 ("Ironically, Defendants adm it they never perform ed any studies on benzene and the effects in pregnant wom en on the fetus."). But the burden is on plaintiff to establish whether her experts' general causation testim ony m eets the requirem ents of Federal Rule of Evidence 70 2. See Moore, 151 F.3d at 276 ("[T]he party seeking to have the 38 m em orandum addresses defendants' argum ents against Drs. Harrison and Bearer, it is silent on defendants' challenge to Dr. Waters' reliability. Moreover, a review of Dr. Waters' report and the studies cited therein reveals that the studies upon which Dr. Waters relies do not reliably support or do not otherwise "fit" her conclusion. Thus, neither plaintiff nor Dr. Waters have dem onstrated the adm issibility of Dr. Waters' proffered expert testim ony. One shortcom ing in Dr. Waters' methodology is that she relies on studies that focus on solvents as a class, rather than on the specific substances to which plaintiff was allegedly exposed. For instance, Dr. Waters cites Khattak, S., et al., Pregnancy Outcom e Follow ing Gestational Exposure to Organic Solvents, 281 J . AM. MEDICAL ASS'N 110 6 (1999),65 for its observation of an association between maternal exposure to organic solvents and developmental m alform ations. Im portantly, the workers in that study were potentially exposed to a wide range of solvents, including phenols, trichloroethylene, vinyl chloride, acetone, and other solvents not at issue in this case. This is problem atic because--as Dr. Waters's report fails to note--the study specifically warned against autom atically ascribing its observations to any district court adm it expert testim ony m ust dem onstrate that the expert's findings and conclusions are based on the scientific m ethod, and, therefore, are reliable."). Plaintiff cannot carry this burden by sim ply questioning defendants' own research practices. 65 Id. at 10 . 39 particular substance: "[O]rganic solvents, although traditionally clustered together, are a diverse group of com pounds that should not be expected to cause sim ilar patterns of reproductive toxic effects." Another shortcom ing is that, like Drs. Harrison and Bearer, Dr. Waters relies without elaboration or explanation on a study that exam ines the risk of spontaneous abortion, rather than the later-stage pregnancy loss that plaintiff suffered. See Ng, T., et al., Risk of Spontaneous Abortion in W orkers Exposed to Toluene, 49 BRITISH J . INDUS. MEDICINE 80 4 (1992) (finding association between spontaneous abortion and specific exposure to toluene).66 Because Dr. Waters fails to explain how this study is relevant, despite its inconsistency with the facts of this case, her citation to it does not prove that a reliable m ethodology underlies her general causation opinion. A third m ethodological defect is that Dr. Waters' report cherry-picks data and fails to explain results that contradict her conclusion. For exam ple, Dr. Waters cites Snijder, C., et al., Occupational Exposure to Chem icals and Fetal Grow th: The Generation R Study , 27 HUMAN REPRODUCTION 910 (20 12),67 in support of her general causation opinion. Dr. Waters' report fails to note, however, that though the study found statistically significant 66 Id. at 11. 67 Id. at 10 . 40 associations involving other chem ical categories, it found no association between exposure to organic solvents--the category containing benzene--and reduced fetal growth. That Dr. Waters fails to discuss this pertinent finding in her report casts doubt on the reliability of her m ethodology. Finally, Dr. Waters relies upon certain studies even though the study's authors were unwilling to reach a causal conclusion. See Joiner, 522 U.S. at 145 (holding that a study did not support an expert's opinion on causation when the study was "unwilling to say that PCB exposure had caused cancer"). In Chevrier, C., et al., Occupational Exposure to Organic Solvent Mixtures During Pregnancy and the Risk of Non-Sy ndrom ic Oral Clefts, 63 OCCUPATIONAL ENVTL MEDICINE 617 (20 0 6),68 researchers observed an association between m aternal exposure to petroleum products and nonsyndrom ic oral clefts. Researchers noted, however, that the number of women who were exposed only to petroleum solvents was very sm all and that "the risk m ay thus be due to the sim ultaneous exposure to both types of organic solvents, chlorinated and petroleum ." Because, as one of plaintiff's other m edical experts acknowledged in his deposition,69 plaintiff was not exposed to chlorinated solvents, this study cannot reliably support Dr. Waters' opinion 68 Id. at 11. 69 R. Doc. 53-1 at 3-4. 41 that the type of exposure alleged by plaintiff can cause oral clefts in the general population. Though Dr. Waters' report states that her brief literature review "represent[s] a sm all sam ple of the studies regarding reproductive health and pregnancy outcom e adverse effects of petrochem ical exposure," there is no evidence that Dr. Waters reviewed any studies other than the five cited in her report in form ing her opinion. Further, Dr. Waters' report provides no indication that Dr. Waters applied the Bradford Hill criteria or any other accepted m ethodology to the applicable literature. Without any explanation of Dr. Waters' m ethodology or application of her analytical m ethods to the literature, the report does not provide a reliable basis for Dr. Waters' opinion. See Moore v. Ashland Chem . Inc., 151 F.3d 269, 276 (5th Cir. 1998) (noting that an expert's m ere "assurances that he has utilized generally accepted scientific m ethodology is insufficient" to establish his reliability). Finally, even if the Court's review of the literature revealed a single study that could plausibly support Dr. Waters' opinion,70 the m ajority of studies 70 Slam a, R., et al., Maternal Exposure to Airborne Benzene and Intrauterine Grow th, 117 ENVTL. HEALTH PERSP., 1313 (20 0 9), observed an association between m aternal exposure to benzene and reduced birth weight and head circum ference during pregnancy and at birth. Moreover, unlike m ost of the other studies upon which plaintiff's experts rely, this study isolated the effects of benzene and m easured exposure levels using diffusive air sam plers. The Court notes, however, that other fetal growth studies have reached the opposite result. Estarlich, M., et al., Residential Exposure to 42 either do not fit Dr. Waters' conclusion or have no apparent connection to this case beyond conclusory ipse dixit. See Knight, 482 F.3d at 355 ("Even if one of the studies relied on by [the expert] provided a plausibly basis for general causation, the district court, after weighing the 'reliability' and 'relevance' of such evidence, finding one or the other lacking, could still reach the conclusion that the evidence was inadm issible."). Under Daubert, the Court m ust evaluate the expert's underlying m ethodology to determ ine whether it is reliable. The Court cannot sim ply accept an otherwise deficient m ethodology because there is a scintilla of m aterial that m ight arguably support the expert's ultim ate conclusion. This is particularly true here because "[i]t is im portant that a study be replicated in different populations and by different investigators before a causal relationship is accepted by epidem iologist and other scientists." Reference Manual at 60 4. Accordingly, the Court finds Dr. Waters' m ethodology unreliable and grants defendants' m otion to exclude her general cassation opinion. Because the Court excludes the general causation opinions of Drs. Harrison, Bearer, and Waters, and there is no other general causation evidence Outdoor Air Pollution During Pregnancy and Anthropom etric Measures at Birth in a Multicenter Cohort in Spain, 119 ENVL. HEALTH PERSP., 1333 (20 11), for exam ple, found no significant relationship between benzene levels and reduced fetal growth. Given these contradictory studies, the Slam a study currently provides only an "inferential starting point" for finding a causal relationship. LeBlanc 39 F. App'x at 99. 43 in this case, the Court need not reach the experts' specific causation opinions or defendants' argum ent against the m ethodology underlying those opinions. See Knight, 482 F.3d at 351 (stating that a court m ay adm it specific causation evidence only after the plaintiff has produced adm issible evidence on general causation). IV. CON CLU SION For the foregoing reasons, the Court GRANTS defendants' m otion to exclude Drs. Harrison, Bearer, and Waters. 4th New Orleans, Louisiana, this _ _ _ day of February, 20 16. ________________________________ SARAH S. VANCE UNITED STATES DISTRICT J UDGE 44
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